Zuolin Zhu

Methylrhenium trioxide as a catalyst for oxidations with molecular oxygen and for oxygen transfer

Abstract Methylrhenium trioxide (MTO) was found to be a good catalyst for the oxidation of tertiary phosphines by molecular oxygen at room temperature. Evidence is given that an intermediate Re(V) compound — CH3ReO2, or the adduct CH3ReO2·OPPh3 — is involved. The deoxygenation of epoxides, sulfoxides, N-oxides, triphenylarsine oxide and triphenylstibine oxide at room temperature was also catalyzed by MTO, with triphenylphosphine as the oxygen acceptor. A plausible reaction mechanism involves phosphine attack at a compound formed between MTO and the epoxide or other oxygen-donor compound.

Catalytic reactions of methylrhenium trioxide on solid oxide supports

Methylrhenium trioxide (MTO), supported on niobia, acts as an effective heterogeneous catalyst for certain chemical reactions. These include reactions of ethyl diazoacetate, which are equivalent to carbene-transfer processes, and selective oxidations that utilize hydrogen peroxide. Both groups of reactions, which are known to occur homogeneously, proceed efficiently and in good yield on the supported catalyst.